Pregnancy can affect vision, but the recommendation that women with myopia have a cesarean section to protect their vision is outdated and useless. In 2015, 21% of births worldwide were by caesarean section, more than double two decades ago.
Natural birth and myopia
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| Natural birth and myopia |
Contents:
- Natural birth and myopia
- What happens to the eyes during the natural birth
- Cesarean section, a useless step for women with myopia
1. Natural birth and myopia
When justified, the procedure saves lives, but it is a major surgery and comes with many risks, including the death of the mother, bleeding and rupture of the uterus and, in the case of subsequent pregnancies, the birth of a stillborn or premature birth.
Consequently, efforts have been made for years to understand what is causing this trend and to identify women who benefit from this intervention unnecessarily.
Women with nearsightedness - difficulty seeing objects at a distance (also known as nearsightedness) due to enlarged eye from front to back, too thick lens or corneal curvature problems - are subject to a number disproportionately high levels of cesarean section, especially in Eastern Europe.
Researchers at the Rijeka University Clinical Hospital in Croatia, for example, found that over a 10-year period in the hospital, women with myopia were 1.5 times more likely to give birth by cesarean section than women who were not myope.
Women who needed the strongest prescription lenses were almost four times more likely to have a cesarean section.
It was thought that during the pushing phase of labor, short-sighted women could be at risk of retinal detachment - a condition in which the retina separates from the lower layer in the back of the eye, which can lead to permanent loss of labor. vision or blindness.
2. What happens to the eyes during the natural birth?
However, from a mechanical or physiological point of view, there is no link to support this, says Samer Elsherbiny, an ophthalmologist consultant at Warwick Hospital, UK. "This is a widespread urban myth."
This myth persists for several reasons. People who are very short-sighted may have a thinner retina, which can break more easily if there are changes in the gelatinous material inside the eye, called vitreous humor, which leads to peeling.
But although venous pressure in the eyes increases when a woman pushes during childbirth, Elsherbiny explains, this pressure has no effect on stained glass humor.
Pregnancy can cause changes in the eyes and vision due to fluctuations in hormones, metabolism, fluid retention, blood circulation and the immune system.
These changes can cause, for example, an increase in corneal thickness and curvature, which can alter vision. Therefore, optometrists generally advise pregnant women to postpone the purchase of new glasses until a few weeks after giving birth and to postpone a decision on LASIK surgery for a few months - a procedure by which doctors use a laser to change the shape of the cornea.
Some doctors also advise women to avoid becoming pregnant in the year after surgery or even to postpone corrective eye surgery until after they have had children, but this advice could be outdated, says Alejandro Fernández-Montero, an occupational physician at the University of Navarra, Spain, who found in 2017 that women have a lower risk of developing or progressing myopia during pregnancy3.
During labor, women are often encouraged to perform the Valsalva maneuver - forced exhalation while the airways are closed - to increase the pressure in the chest and stomach to push.
This increase in pressure does not cause retinal detachment but can lead to rupture of the capillaries in the eyes and impaired vision, a condition known as Valsalva retinopathy. But in general, it is not serious and usually resolves on its own.
Caesarean section is not usually recommended for pregnant women with pre-existing eye problems, such as diabetic retinopathy, a condition caused by high blood sugar that damages the retina, says Janet Sunness. Richard E. Hoover Low Vision Rehabilitation Services in Towson, Maryland.
His advice also extends to women in the more advanced stages of the disease, when abnormal blood vessels can lead to bleeding or detachment of the retina. "The evidence is not strong enough for her to have a cesarean," says Sunness.
But the lack of evidence has not prevented many women from having a caesarean section because they have an eye condition.
3. Cesarean section, a useless step for women with myopia
The exact number is difficult to say, but in 2010, Polish researchers reported that 2% (100 out of 4,895) of cesarean sections performed between 2000 and 2008 at Dr. Jan Biziel University Hospital no. 2 of Bydgoszcz were performed following a written recommendation from an ophthalmologist.
In almost half of the cases, eye problems were the only reason for the procedure, myopia being at the top of the list of ophthalmological reasons.
Efforts are being made to reduce the number of cesarean sections performed due to eye conditions.
In 2003, following the results of the Croatian study, which showed that almost 40% of women with severe myopia in a hospital underwent caesareans, the then director of the hospital's obstetrics and gynecology department, Oleg Petrović, changed the hospital's policy to say that great myopia is not enough as a reason for a cesarean section.
To ensure that this decision did not adversely affect either women's eye disease or pregnancy outcomes, Petrović conducted a second study between 2003 and 2007, involving 240 women.
His team said that whether women had low, medium or high myopia, the change in policy did not increase the number of eye complications.
In 2015, Trnava University Hospital in Slovakia similarly stopped performing cesarean sections for ophthalmological reasons. Between 2010 and 2014, before the new policy was introduced, cesarean sections related to eye conditions, such as myopia, accounted for 1.8% of all such hospital operations.
However, in some places, the practice remains common, such as in rural areas and in small hospitals in Romania, where both doctors and patients are accustomed to this practice, says Corina Taban, ophthalmologist at the Children's Clinical Hospital Dr. Victor Gomoiu from Bucharest.
It is the duty of obstetricians who are familiar with this problem to educate their colleagues, says Petrović.
Breaking the bad link between myopia and cesarean section, he says, "could lead to a reduction in the number and frequency of cesarean deliveries worldwide, as well as an improvement in maternal mortality and morbidity."